1. Field of the Invention
This invention relates generally to tire deflating devices for removing the air from a tire, and more particularly to such a device for quickly deflating a tire to a lower pressure while providing means for measuring the tire pressure at any point in the deflation process.
2. Description of Related Art
Invention and Use of devices in the field of the invention is known to the public, as they are used for similar purposes as defined herein. The following art appears to be most relevant to the present invention.
McMahan, U.S. Pat. No. 2,320,042, describes a tire filling means for filling a tire with water or other liquids. The device uses a valve core remover held within a tube. The core is removed and translated to one end of the tube. Then a valve is adjusted to inlet the fluid through an inlet port at one side of the tube. When the tire is filled with the fluid, the core is replaced.
Sullivan, U.S. Pat. No. 2,592,759, describes an adapter for use when filling the tubes of vehicle fires with a liquid. A plug cock body has four short pipes integral with it. Two of the pipes are in line and attach to the tube valve stem for air outlet. The other two pipes are in line and at an angle of about 40 degrees to the other pair. These are for attachment to a gauge and to a supply pipe. A hollow plug in the body provides an aperture which may be positioned out of register with all of the pipes when the register is closed. In this position, a valve extractor assembly is connected to the air outlet pipe. When the plug is turned to a second position, the valve extractor stem is pushed through the aperture in the plug and the valve is removed. When the plug is moved to a second position, a predetermined volume of air escapes from the tube. When the plug is mined to a third position water is admired to the tube and a bleeder tube assembly is attached to the air outlet pipe.
Blomgren, U.S. Pat. No. 2,656,083, describes a tire adapter for removing the tire valve for filling the tire. The adapter is of a clear material making it possible to observe the mechanical operation and the passage of a liquid under pressure into a tire. The valve removing means and liquid inlet means are part of the same member and enter the housing through the same opening.
Itoh, U.S. Pat. No. 3,548,651, describes a pocket tire pressure gauge for checking and adjusting tire pressure. It includes a manually adjustable scale-set relief valve in direct communication with a member for connecting to a tire valve. This allows blowing-off of excess pressure in a tire, and optionally provides an air inlet opening also in direct communication with the connecting member, to receive an air hose by means of which a tire can be inflated through the gauge to the required pressure, the air inlet is provided with a shutoff valve, to prevent escape of air through it when an air hose is not connected.
Mazeika, U.S. Pat. No. 3,429,332, describes a replaceable cartridge gauge for use in garages, service stations, and the like, for inflating and deflating vehicle tires, air tanks, and other such pressure vessels and indicating the air pressure within, in which the valve and it associated pressure indicator bar are assembled as a single unit which is removable for replacement or repair purposes as a unit from the valve housing and the barrel of the air extension tube.
Featherstone, U.S. Pat. No. 3,724,488 discloses a combination seal cap and valve for use with a standard pneumatic tire stem valve having an outer sleeve internally threaded at one end for an internal threadable engagement with a standard valve stem and internally threaded at another end for threadably receiving a standard stem valve. A tapered plug member captured within the outer sleeve and dimensioned for sealing the standard valve stem when the outer sleeve is snugly mounted thereto and for allowing an air passage through said sleeve and said standard valve stem into a tire when backed off from a snug installation.
Morrell, U.S. Pat. No. 3,844,530 discloses a flare fitting assembly which is described comprising a pair of flare fittings, at least one of which is threadably fitted with a Schrader-type valve, and a separable Schrader-type valve actuating member. The valve actuating member is provided with a central receiving cup for releasably capturing the end of a valve stem extending from the valve. The actuating member serves to depress the valve stem and open the valve as the fittings are coupled together. The central receiving cup of the member serves to maintain the member axially aligned with respect to the axis of the fittings and releasably retain the member on the stem when the fittings are decoupled.
Ross, U.S. Pat. No. 4,276,989 discloses a delivery system which functions under pump pressure to introduce a fluid such as a sealant interiorly of a pneumatic vessel such as a tire through the air valve without deflating the vessel. A valve core extractor functions in a pressurized atmosphere to remove and retain the valve core without loss of pressure. A pump, including a resilient one-way check valve, introduces the fluid through the valve, also without the loss of pressure. Following introduction of the desired quantity of the fluid, the valve core extractor is functioned in reverse to reinsert the valve core, all without loss of system pressure.
Leimbach, U.S. Pat. No. 4,445,527 discloses a tire valve extension (10) which includes a relief valve element (24) to limit the inflation pressure of the tire. The extension has a tubular body with an annular recess (36) formed therein to define an outer tube section(14) and an inner tube section (16). A spring loaded valve actuating pin (18) is received within the inner tube section, and the relief valve element is received within the recess. Ports (32) formed in the body intersect a channel (38) formed in the recess to define a relief flow path.
Kleeman, U.S. Pat. No. 4,569,363 discloses a hand held mechanism that can be applied to a conventional tire inflation valve on a vehicle tire to facilitate a tire deflation operation. The mechanism includes a rod-like element that automatically engages a tire check valve to open said valve for tire venting purposes. The mechanism also includes a hollow tubular wall structure adapted to receive the sensing head of a conventional pressure gage, whereby the progress of the tire-deflation operation can be ascertained, as necessary to properly terminate the operation at a desired tire pressure. Mechanisms of the described type can be utilized on all wheels of a multi-wheeled vehicle to permit simultaneous deflation of all vehicle tires, thereby greatly reducing the time required to achieve a total tire deflation operation.
Klink, U.S. Pat. No. 5,325,886 discloses an apparatus for inflating a tire, connected to a tire rim, and indicating the pressure of a tire while the tire is on the rim. This apparatus includes an elongated body element for connection with the tire rim, an elongated valve element having indicia thereon slidably disposed within an elongated passageway within the body element, a seal attached to the valve element, and a spring for biasing the valve against movement toward an extended position. The valve is moveable to a fully retracted position within the body and allows pressurized air to flow between the body and the valve when the apparatus is used to fill a tire.
However, the prior art does not teach a means for deflating a tire in an accelerated manner while permitting intermittent determination of the actual pressure level in the tire as it is deflated. The present invention fulfills these needs and provides further related advantages as described in the following summary.